A gas generator with a container, which is filled with a pressurized fluid and has an outflow opening, is usually denoted as a cold gas generator, in which the filling gas intended for inflating a gas bag is stored in compressed form in a container for compressed gas. As filling gas, principally inert gases such as argon or helium are used. Compared with solid propellant generators, this type of gas generator offers the advantage that the generated gas is particle-free and, in addition, compared with a pyrotechnic gas generator, it arrives into the gas bag with a distinctly lower temperature. Of course, in cold gas generators it is considerably more costly to realize an outflow behavior of the gas from the gas generator which is adapted to the respective installation situation.
It is known that the outflow behavior can be influenced through equipping the pressure container with a shutter having a small shutter opening. The maximum in the mass flow of the emerging gas is all the less, the smaller the volume in the chamber formed between shutter and outflow opening, and the smaller the shutter opening is itself. A reduction of the emerging quantity of gas by reduction of the chamber volume with a given pressure in the container is therefore always accompanied by a reduction of the maximum in the mass flow. However, this maximum must not fall below a certain value, because this so-called initial strike must provide a sufficiently high force in order, for example, to press open a covering of a gas bag module or to ensure an initial unfolding of a gas bag. Therefore, close limits are set for the variation of the outflow behavior. The fixed arrangement of a shutter in a compressed gas container is, in addition, relatively costly.
It is an object of the invention to make possible in a simple manner a variation of the outflow behavior of the gas from a gas generator.